OMRI does not recommend using pet poop for the garden. Cat litter comes in a couple of forms, the older clay litter (it is useful to sop up oil spills on the garage floor BTW) it does not clump. The newer cat litters are finer and clump when wet , so you really would not want that in the garden at all. The biodegradable newspaper pellet litter...my cat refused it, she did not like the texture or feel of it when she dug in it , so I never got more than one bag. I actually did try to train my cat to use the toilet, but that didn't work out. I'd pay somebody to do that, it would be worth it not to have to clean out the box every day.
If you want to get rid of cat and dog poop, you can install a doggie dooley. It uses bacteria to break down the poop and it is fine if it is installed near turf grass unless you plan to eat the grass.
https://www.doggiedooley.com/how-does-it-work-.html
Happy gardening in Hawaii. Gardens are where people grow.